Why carbon dioxide matters
Carbon dioxide (CO2) is a greenhouse gas: a gas that absorbs heat, and releases it gradually, over time. It’s the most important of Earth’s long-lived greenhouse gases: although it absorbs less heat (per molecule) than other greenhouse gas emissions, like methane or nitrous oxide, there is more of it, and it stays in the atmosphere for longer.
Sunlight warms the Earth’s land and ocean surfaces, which continuously radiate thermal infrared energy (heat). Without this natural greenhouse effect, the Earth’s temperature would drop below freezing. Most of the seas would turn to ice, and it would be so cold that most of life on Earth would not survive.
Increases in atmospheric CO2 have tipped the climate change balance. The Earth’s carbon footprint is too large. Rising CO2 levels generating additional heat mean the Earth’s average temperature is rising, faster than at any time in the past 100,000 years. Human-induced climate change has serious implications for our planet, and its future.
Global warming is playing havoc: winters are colder, summers are hotter; Polar ice caps are melting and sea levels are rising; entire ecosystems are being destroyed. Animal populations are declining at an alarming rate, and so, climate change is being heralded as the sixth extinction.
